Robot assemblies are an important component in automation, especially in manufacturing facilities and manufacturing equipments. For example, in the semiconductor industry, robot arms are used to handle semiconductor wafers, flat panel display, LCD, reticles, masks, or carrier boxes.
In the semiconductor fabrication facility, robot can be used to transport work pieces, typically stored in carrier boxes, from one location to another location, from one equipment type to another piece of equipment. In a process system, a robot is typically used to remove the work pieces from the carrier boxes, and then load them into a load lock. Another robot can be used to move the work piece from the load lock into a processing chamber and from one processing chamber to another processing chamber. Thus within a processing system, there might be a plurality of robots, each one is designed for a particular task. The processing system could be a deposition system, an etch system, a lithography system, a metrology system, an inspection system, an implantation system, a treatment system, or any work piece processing system.
Semiconductor fabrication processes require high level of cleanliness, and thus impurities such as contaminants or particles must be prevented as much as possible from entering the clean environment during the production of the semiconductor device. Conventionally, clean environments include a fan and filter unit (FFU) that circulates the air through the clean environment and filters the air entering the clean environment. Thus particles generated within the clean environment remain in the clean environment until being exhausted. To achieve the desired cleanliness, it is desirable to minimize the number of particles generated in the clean environment, especially for transfer robot with many moving parts.